How is the Earth Changing?
In this unit, students investigate plate tectonics by investigating how the Earth has changed in the past and continues to change today. The unit begins with a historical perspective as students learn how the theory of plate tectonics was developed through the social processes of evidence gathering and explanation in the scientific community. Students then explore the modern explanation for why plates move on Earth’s surface by applying their understanding of convection, built on previous study of convection in the atmosphere, to the Earth’s mantle. They investigate how these internal earth processes drive plate motion and how that motion leads to events such as earthquakes and eruptions, and shape major surface features on Earth, including volcanoes, mountain ranges, islands, and oceanic trenches. They use this conceptual understanding to explain features and events found in selected case-study sites around the world.